From: Heinz Diehl <htd@fancy-poultry.org>
To: linux-kernel@vger.kernel.org
Cc: Frederik Himpe <fhimpe@telenet.be>,
USB list <linux-usb@vger.kernel.org>,
Alan Stern <stern@rowland.harvard.edu>
Subject: Re: Logitech HD Webcam C525 does not work when connected to USB 2 port, works on USB 3
Date: Wed, 11 Jul 2012 08:11:14 +0200 [thread overview]
Message-ID: <20120711061114.GA1596@fancy-poultry.org> (raw)
In-Reply-To: <Pine.LNX.4.44L0.1207051712170.13212-100000@netrider.rowland.org>
Hi,
I have exactly the same webcam, lsusb says "Bus 002 Device 004: ID
046d:0826 Logitech, Inc."...
On 06.07.2012, Alan Stern wrote:
> On Thu, 5 Jul 2012, Frederik Himpe wrote:
> > I tried setting to on again, and then this appears in the logs:
> > Jul 5 21:21:59 piranha kernel: [ 9788.223118] usb 1-1.2: USB disconnect, device number 6
> > Jul 5 21:22:00 piranha kernel: [ 9788.330415] usb 1-1.2: new full-speed USB device number 7 using ehci_hcd
> > Jul 5 21:22:00 piranha kernel: [ 9788.402207] usb 1-1.2: device descriptor read/64, error -32
> > Jul 5 21:22:00 piranha kernel: [ 9788.577706] usb 1-1.2: device descriptor read/64, error -32
> > Jul 5 21:22:00 piranha kernel: [ 9788.753203] usb 1-1.2: new full-speed USB device number 8 using ehci_hcd
> > Jul 5 21:22:00 piranha kernel: [ 9788.824996] usb 1-1.2: device descriptor read/64, error -32
> > Jul 5 21:22:00 piranha kernel: [ 9789.000493] usb 1-1.2: device descriptor read/64, error -32
[....]
...and I do not have these messages at all, with or without
autosuspend enabled...
> In the long run, it may be necessary to add a quirk entry to always
> use a reset-resume with this device. You can find similar entries in
> drivers/usb/core/quirks.c for other Logitech webcams, which makes it
> seem very likely that one is needed for yours. If you want you
> can try adding the appropriate entry and submit it as a patch.
...and it runs fine with or without the quirk, which I added for
testing purposes.
> None of this explains why there isn't any problem when the webcam is
> plugged into a USB-3 port, unfortunately.
All this is purely on USB-2, my machine doesn't have any USB-3 port,
with vanilla 3.4.4 kernel. If nobody did, should I submit a patch
containing the quirk anyway?
If I can help testing, feel free to contact me.
prev parent reply other threads:[~2012-07-11 6:11 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-06-30 19:21 Logitech HD Webcam C525 does not work when connected to USB 2 port, works on USB 3 Frederik Himpe
2012-07-01 2:12 ` Alan Stern
2012-07-01 12:34 ` Frederik Himpe
2012-07-01 15:54 ` Alan Stern
2012-07-02 20:12 ` Frederik Himpe
2012-07-03 0:40 ` Alan Stern
2012-07-04 18:21 ` Frederik Himpe
2012-07-04 18:42 ` Alan Stern
2012-07-04 20:19 ` Frederik Himpe
2012-07-05 1:20 ` Alan Stern
2012-07-05 19:35 ` Frederik Himpe
2012-07-05 21:24 ` Alan Stern
2012-07-11 6:11 ` Heinz Diehl [this message]
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